http://wiki.mabinogiworld.com/view/Combat_Power_Modifiers
I have no idea how much raccoon cub wizard suits are worth now, but since that one gacha was spitting them out hopefully the prices aren't too high.
Best shield es is abysmal, gachas have given them out before, either on cooking pots or Avon shield (expensive).
The other enchants that aren't extremely difficult to get require a bit of bridging and a lot of Karu spamming.
Damaging gauntlets (r9 suffix), es from Karu stone zombie dungeon, -100cp
Inconvenient metal footwear (r8 suffix) from Karu stone imp dungeon, -100cp
Uncomfortable metal helmet (r8 suffix) from Karu stone hound, -100cp
Thin headgear (r8 prefix) from Lingering Darkness int+, or Their Method HM, -100cp
Small gloves (r8 prefix) from Enemy Behind all difficulties, -100cp
Vicious footwear (r8 prefix) from Their Method int+, -100cp
So you can get:
Thin Uncomfortable metal helm: -200cp
Vicious Inconvenient metal footwear: -200cp
Small Damaging gauntlets: -200cp
for -600cp total.
Add in your body es, you would lose 500 more cp for -1100cp total (-1600 with raccoon cub)
Abysmal shield (-500cp) and a scrap (-500cp) weapon would be ideal but hard to get, and would net you -2600cp in total reduction.
Easier weapon would be a Broken Arrow crossbow (-250cp)
tl;dr
Thin Uncomfortable metal helm: -200cp
Vicious Inconvenient metal footwear: -200cp
Small Damaging gauntlets: -200cp
Raccoon Cub or -500cp body
Broken arrow crossbow (-250cp)
total: -1350/-1850 cp